And I'm Steve Inskeep. Good morning. Here's the latest on the crisis in Syria. The U.S. State Department says it has closed the U.S. Embassy in Damascus, and evacuated its diplomats. The U.S. also issued a warning for all American citizens to leave the country immediately. A State Department spokewoman says the embassy was shut because of concerns that it's not sufficiently protected from armed attack.

That comes after a bloody weekend, as Syria's government continues hammering protesters. According to activists, an assault on the city of Homs included artillery that struck a makeshift medical clinic. We'll hear more about that in a moment.

The latest fighting came during the same weekend the United Nations failed to condemn Syria. At the U.N. Security Council, Russia and China vetoed a resolution that was essentially calling for Syrian President Bashar al-Assad to give up power.

We spoke earlier today with NPR's Kelly McEvers, who is monitoring the situation from Beirut.

I want to begin by mentioning the United Nations did not act over the weekend, and yet people are asking if the very failure to act may itself affect the situation in Syria.

KELLY MCEVERS, BYLINE: You know, activists and opposition leaders on the ground in Syria say that this failure to act has given the Syrian regime what they call a license to kill - to keep on continuing attacking protesters and opposition groups on the ground. And that's exactly what we've been seeing over the weekend. More attacks have continued in the anti-government city of Homs.

INSKEEP: What sort of attacks?

MCEVERS: Well, what we're seeing is mostly artillery and mortar bombs and rockets, so indirect fire coming into neighborhoods in Homs that have largely been held by opposition groups. What you have inside Homs - I just spoke to someone who just came out of Homs, and you have these neighborhoods, these pockets of resistance, that are basically under the control of the opposition. They man checkpoints in the outside of the neighborhoods. But government forces sort of surround the city, so they can launch these indirect fire attacks into the neighborhoods themselves.

And then they also perch snipers along major thoroughfares so even during times of quiet, when people are trying to move from place to place, they'll get hit by gunfire.

INSKEEP: Is this how this medical clinic got struck?

MCEVERS: Right. Just today, what's been happening is, they've been shelling this one particular neighborhood called Baba Amr. It's long been a center of protest. Just listen to this clip from a citizen journalist in Homs. His name is Danny Abdul Dayem. He's inside this makeshift field hospital.

DANNY ABDUL DAYEM: We're not animals; we're human beings. We're asking for help. We're asking for your help. They're hitting us with rockets. There's been no stopping those rockets for four hours now. They're going to kill us all.

MCEVERS: So he's talking about the rockets that were hitting the neighborhood. But not long after this video was shot and sent out, the hospital itself was hit by a rocket, and so there were more injured inside the hospital itself.

INSKEEP: Now, Kelly, we should be clear: Few, if any, journalists are inside Homs, or in any of the contested areas in Syria. We're getting information from activists here. How confident are you of the picture that's emerging, of what's happening in Syria right now?

MCEVERS: It is so difficult to verify the numbers. And over the weekend, we saw that there were discrepancies about how many, exactly, had died in some of these government offensives. You had one activist group saying it was over 300. Another activist group saying no, it was only 60. And without being able to go there ourselves and verify it and see it with our own eyes, it's very difficult.

But what we have done is - we work with organizations that corroborate their information, that have lists of names. We double check. You know, we work with people who we've known, who our colleagues have met in person the few times that people have managed to get into Homs, and that's what we go with.

INSKEEP: So as that fighting continues in Homs and perhaps in other parts of Syria, what are countries on the outside doing now that the United Nations Security Council has failed to act?

MCEVERS: Well, U.S. Ambassador to the United Nations Susan Rice spoke to NPR over the weekend. And here's what she said.

SUSAN RICE: We certainly will look at every means at our disposal to increase pressure on Assad. His days are numbered. There's no question that this regime cannot endure. The only question is, how many people will die before it ends?

MCEVERS: And she's speaking about Syrian President Bashar al-Assad. The U.S. secretary of Secretary State, Hillary Clinton, sort of upped the ante another step over the weekend. She said that countries that oppose this regime should come together and form a quote-unquote, friends of Syria group - sort of like the contact group on Libya that worked with the opposition.

Now, the U.S. has been very clear that at this time, it wants to provide only political support to the Syrian opposition. But what we're hearing now is a lot of talk about other countries - Gulf Arab countries, Turkey talking about arming the opposition in Syria.

So what does that mean? That means that this conflict that's already looking like a civil war may, at some point, have outside actors. You've already got Russia arming the Syrian regime. Now, you've got countries talking about arming the Syrian opposition. So that turns into something even bigger than just an internal conflict. That sounds more like a proxy war, and that's got analysts here in the region very worried.

INSKEEP: Kelly, thanks very much.

MCEVERS: You're welcome.

INSKEEP: That's NPR's Kelly McEvers, reporting on the situation in Syria from her base in Beirut. Transcript provided by NPR, Copyright NPR.